Update field visualization for 2023

Kept things pretty rudimentary so far, but this keeps the core
functionality that we had in 2022 for understanding the localizer.

Change-Id: I566d6ebc2dead414b11e92d41fde78dd70f34e92
Signed-off-by: James Kuszmaul <jabukuszmaul@gmail.com>
diff --git a/aos/util/error_counter.h b/aos/util/error_counter.h
index 9fbe242..3e69a71 100644
--- a/aos/util/error_counter.h
+++ b/aos/util/error_counter.h
@@ -80,7 +80,7 @@
   ArrayErrorCounter() { ResetCounts(); }
 
   flatbuffers::Offset<flatbuffers::Vector<flatbuffers::Offset<Count>>>
-  PopulateCounts(flatbuffers::FlatBufferBuilder *fbb) {
+  PopulateCounts(flatbuffers::FlatBufferBuilder *fbb) const {
     const flatbuffers::Offset<flatbuffers::Vector<flatbuffers::Offset<Count>>>
         offset = ErrorCounter<Error, Count>::Initialize(fbb);
     flatbuffers::Vector<flatbuffers::Offset<Count>> *vector =